Fluid change and reversing gear.



H. LENTZ. FLUID CHANGE AND RBVERSING GEAR.

APPLICATION FILED OUT. 21, 1914.

Patented Feb. 9, 1915.

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Specification" of Letters ream.

Application am October 21, ran. earn-no. eraser.

Tamil whcm vltmay concern:

it known that I, HUGO Laure, a citirien of the German Empire, and resident of Berlin-Halensee, Germany, have invented certain new and 'usetul Improvements in Fluid Change and Reversing Gears, of which the following is a-specification.

My invention relates to improvements in I vide a gear of this class by means of which a setot fluid operated motors is connected at least with two sets of umps'in such a way that the pressures o the fluid transmitted from the sets of pumps to the set of motors cause a balancing of the pressures onthe set of motors.

Another object ofthe improvemenm is to provide by-passages end compensating passages by means of which the direction of rotation of the driven shaft can easily be reversed,-and which in-case of non-uniform power ofthe sets of pumps compensate the power'within the gear.

For the purpose of explaining the invention an example embodying the same has heen shown in the accompanying drawing,

' which is a section of the gear in which the controlling elements-are shown-in the positions for forward movement of the driven mover.

lln the enample'shown in the drawing two sets of pressure pumps 5 and o a'nd-a-set of motors d of the "construction common in rotary machines are located Within-a casing a. The two sets of pressure pumps'h and c are disposed symmetrically and at opposite sides of the set of motors 01, and the chamhers e, f, and g, h of -said pumps are connected with the motors d through p'assages e, f and g, 71, respectively which are located tangentially of the sets of pumps and motors. The said passages are equipped with controllin members or valves 2', 7a and Z, m respectively. In the symmetrical arrangement shown the two passages e, h which have the same function are parallel to each other, and the same thing is true of the other pairof .pasmgessr g, anrl't mtwo passagesof a pair lead to the motor d at diametrically-opposite:points. x

The chambers e, 72, are pressure chamhers, and the chambers ff, are suction chambers when the pumps -rotate =.in the direction indicated in the drawing, and the passages e lrare pressure passages, while the-passages f, 95 are suction gpussages when the walves i, t e t, m, are in the position shown in fullh'nes. lln the casing a there are arranged laterally passages an, =00, s, and t. v01 these, the passages an and on leadfrom the pressure passagese =.anrl-' it respectively to-the controlling members i}: and

' Z respectively, which according to their position will establish or interrupt the connec tion of said'passages am and on with suction chaurrrihers f and g respectively. The compensatlng passage .9 connects the passages e and'a with the passages hand-o,

while the compensating passage t connects the passage f with the passage g.

The operation of the apparatus'is'as tollowsz Vvhen theapparatus is moving in forward direction the controlling members '1 and leer land at are in thepesitions shown in the drawing. The shafts p and g of the two-sets of :pressure pumps 79 and care drivenin the same direction-.eachby razprime mover. The aPI-BSSHIQ fluid (ordinarily a non-el-astic'fluid) is forced from-orient we sets-ct pumps, Z), to one side of the set'of motors, 0i, and from the other set oihpumps,

,. c, to-thc opposite'side (if-the set of'motors d, so that the driven shaft is not 'subject'to transverse pressure. Furthermore the current of the fluid moves in the form of a single elliptical hand within a plane perpendicular to the shafts without being deflected from the said plane, so=that the current of the fluid is not subjected to any material resistance.

When ll-speaker the fluid as movingin the form of 'a"single'elliptical'hand, I-tnean that the path of the fluid is a closed curve symmetrical to two axes which are perpendicuhi-r to each other; of course, the path shown in the drawing is not a true elllpse. The major axis of said elliptical path extends through the axes of the pumps h, a and motor (5. It will be seen that there are two entirely separate paths throughwhich the liquid from the delivery port of one pump passes to the suction port of the other pump. Thus for instance the path of the pensating passages 8, and t in the following way: For example, if the set 6 of the pumps forces more liquid, one part of thesaid liquid actsin the regular way onthe blades of the set (5 of the motors, while the other i part of the liquid flows through the passage a to the other side of the set of motors and acts within the latter in the same direction on the blades. Of course, in this case the pump b will draw liquid partly through the passage 7 and partly through the passage t. The same is the case if the set 0 of pumps forces a greater amount of liquid.

If it is desired to reduce the'speed, thepump pistons of one set of pressure pumps are thrown out of operation, as is known in the art. If it is desired to stop the driven shaft 7 the two sets of pressure pumps are short-circuited by setting the controlling valves in the proper way that is to say, the

valves is, Z, are left in the position shown in I full lines, but the valves 2', m are placed in the position indicated by dotted lines. As

a result, the liquid expelled by the pump 6 through pressure chamber 6' will return to said pump through the passage f and suction chamber f, and at the pump a, the

liquid will pass from the pressure chamber it directly to the passage 9 and to the suction chamber 9. To reverse the motor, the

- four valves 71, is, Z, m are placed in the position indicated by dotted lines, which will cause the liquid to flow through the following path: From pump 12 through chamber e, passage 7, motor d, passages h, 0, chamber 9, pump 0, chamber h, passage 9, motor (2, passages e and n, and back to pump 1 through chamber f.

While indescribing the invention reference has been made to an example in which two sets of pumps of equal power are provided, I wishit to be understood that my invention is not limited to this feature, and that more than two sets maybe provided, and that the pumps may be so constructed as to develo different powers. I Also in this case the riven shaft which rotates at lower tions of t e owers of the sets of fpumps are balanced wit in the gearing itsel the combination with a fluid motor, of pressure pumps, and suction and pressure passages for supplying the pressure medium from saidpumps to the motor for driving the same, the discharge ends of the pressure passages being arranged symmetrically of the motor, whereby the fluid pressures acting on the motor are equalized relatively to the said motor, controlling members in said suction and pressure passages, and passages connecting the pressure and suction passages of the pumps.

2. In an apparatus of the class described, the combination with a fluid motor, of pressure pumps, and suction and pressure passages for supplying the pressure medium from said pumps to the motor for driving the same, the discharge ends of the pressure passages being arranged symmetrically of the motor, whereby the fiuid'pressures acting on the motor are equalized relatively to the said motor, controlling members in said suction and pressure passages, and compensating passages connecting the pressure and suction passages of the pumps between the controlling members and the motor, whereby differences of the power developed by the pumps are balanced.

In an apparatus of the class described, the combination with a rotary fluid motor, and rotary pumps located at opposite sides of said motor, the axes of said pumps and motor being parallel to each other and lying in the same plane, of passages connecting b is speed erfectly balanced" and' thd'warim 6B 1. In anapparatus of the class described,

said motor and pumps and forming a continuous path of substantially the form of an ellipse whose major axis passes through the axes of the motor and of the pumps.

In testimony whereof, I have signed this specification in the presence of two subscrib- 

